Nobody can tell you anything without proper system info or other technical details like version of AE and details about the projects/ comps. Apparently this refers to an issue with LUTs, but without knowing where you used them and which ones, nobody can even guess.
I'm working on a iMac 5K with the full Adobe creative Cloud.
The AFX document original is made in After Effects 2015.3. I tried to open it in the latest version After Effects 2017 then it crashes. I re-installed After Effects 2015.3 but the same document crashes also in this version. I use several plugins (for example Digieffects, RedGiant, VideoCoPilot and have some scripts (audio to markers, a try-version of automatic editing).
I do not know which effects are used in the compositions which crash. thats the problem.
Does that help?
RedGiant Magic Bullet Film crashes ...
After several hours in a remote session with Adobe's support engineer Rahul problem solved. It's the RedGiant Magic Bullet Film crashing these projectfiles. Although the plugin is up-to-date says Red Giant on their site. I'll report the error to them. Thanx again Rahul you saved my projects!